1. Field of the Invention
The present invention relates to a malfunction preventing device for an air bag module in automobiles, in which upon occurrence of a crash accident of an automobile, an air bag is rapidly inflated to prevent a driver from colliding against a steering wheel, a front glass or the like.
2. DESCRIPTION OF THE PRIOR ART
In automobiles having an air bag module detachably mounted on a steering wheel, which module comprises an air bag, an inflater adapted to rapidly supply a high pressure gas into the air bag, and a deceleration sensing mechanism for operating the inflater when a deceleration of a vehicle body has been increased to a level higher than a given value, there is conventionally known an apparatus wherein in order to prevent the malfunction of the module when separated from the steering wheel, a locking mechanism adapted for engagement with the deceleration sensing mechanism to maintain the latter inoperative is operated in the condition that the air bag module has been detached, as described, for example, in Japanese Patent Application Laid-open No. 78536/78.
In the above prior art apparatus, the exclusive locking mechanism operable with removal or detachment of the module should be specially added to the deceleration sensing mechanism having a complicated structure from requirement for a high accuracy. This results in the over-all arrangement being complicated and in an increased cost. Additionally, there is also a fear of reduction in operational precision for the deceleration sensing mechanism.